Hi,
Before you begin, you must do the following:
Create an Excel workbook that has one or more cells, each defined as a named range, designed to accept values, such as a mortgage calculator that calculates a monthly payment based on the length of the loan in years.
Publish the workbook to Excel Services, and make sure that you define a parameter for each cell that accepts values.
1. On the worksheet, select the cell that you want to make editable in the browser and Excel Web Access.
2. On the Formulas tab, in the Defined Names group, click Define Name.
3. In the Name box, type the name that you want to use for the parameter.
4. Click OK.
5. Click the File tab, click Save & Send, and then click Save to SharePoint.
6. Click Save As, and then click Publish Options.
If the Publish Options button is unavailable, your version of Excel does not support publishing a workbook to Excel Services.
7. On the Parameters tab, do one of the following:
To add parameters, click Add, select the check box of the parameter that you want to add, and then click OK.
To delete specific parameters, select them in the list of parameters, and then click Delete.
To delete all parameters, click Delete All.
Note Workbook parameters are stored in the workbook that you publish to Excel Services.
The article below is about how to define workbook parameters
for use in Excel Web Access.
https://support.office.com/en-us/article/Define-workbook-parameters-for-use-in-Excel-Web-Access-188f2ffc-87ec-482b-8ecf-72f4a8d994b3
After you have defined workbook parameters, you could connect the filter web part to excel web access web part. You could follow the steps below, and I use the text filter web part as example:
1. To modify the Web Part Page, click Site Actions, and then click Edit Page.
2. Add the Text Filter Web Part and the Excel Web Access Web Part to a Web Part Page.
3. From the Text Filter Web Part, click the Web Part menu, point to Connections, point to send Filter Values From, and then click the name of the excel web access Web Part.
4. In the Configure Connection dialog box, select the parameter from the Filter Parameter list, and then click Finish.
5. Save the page.
Best regards,
Sara Fan